[mike31154]

Have you considered LEDs? Still a bit costly but for a Nano probably ideal. Plenty of flexibility for spotlighting a particular area for something like a BTA. Low power, low heat, great light output if you get the right combo.... Although, I just reread your last post and since you already have HQI, yeah, might be just as well to stick with it for the time being. LEDs will continue to drop in price and you can do some research on them while your HQI does its thing. Depending on the bulb you currently have, it will be good for at least a year before needing replacement. Regarding PCs, I think they're on the way out, that technology has run it's course as far as most marine systems go. Not the greatest selection, if you're going to go any kind of fluorescent, T5HO offers much more.